A mail creation system, in general, has an enclosure supply section, an insertion station and a closing and sealing station. The enclosure supply section has a gathering section where the enclosure material is gathered before it is inserted into an envelope in the insertion station. This gathering section includes means to gather the various components of the mail piece into a coherent set, and may include a folder sub-system for folding the coherent set into a packet for insertion into an envelope. If the enclosure material contains many documents, these documents must be separately fed from different enclosure feeders, or may be sequentially fed from a single feeder, or created as individual printed sheets by a printer included in the gathering section. After all the released documents are gathered, they are put into a stack and may be folded into a packet to be inserted into an envelope in an inserting station. Envelopes are separately fed to the inserting station, one at a time, and each envelope is placed on a platform with its flap opened. At the same time, mechanical fingers or a vacuum suction device are used to keep the front face of the envelope on the platform while the throat portion of the back face of the envelope is moved upward to open the envelope. The stack of enclosure material is then automatically inserted into the opened envelope.
A typical mail creation system 1 is shown in FIG. 1, which has an enclosure supply station 20, an insertion station 100 and a flap closing and sealing station 30. As mentioned above, the enclosure supply station 20 can be an enclosure gathering station and may include a folding station. After the enclosure is inserted into an envelope in the insertion station 100, the flap on the stuffed envelope may be moistened, then closed and sealed. This can be carried out at the station 30. The station 30 may have a postage meter to provide a postage indicia on the envelope or a printer to address the envelope. Alternatively, the address may be put on the envelope before the envelope is advanced to the inserting station. Or, if the envelope is a windowed envelope, no addressing may be included in the process. The processed mailpieces are typically stacked.
Traditionally, it has been known that the step of opening the throat of an envelope is usually the most trouble prone portion of an insertion system. Paper jams, incomplete insertions, and damage to the envelopes are some of the common faults experienced on the current state-of-the art equipment. In some equipment, vacuum systems are sometimes employed to increase the reliability of the envelope throat opening operation. But this method is relatively expensive, and often requires operator adjustments for optimal performance.
In essence, the problem with traditional insertion fingers is that they can exert unwanted drag forces on the envelope while the envelope is being moved into the insertion area, and further exert unwanted drag forces on the packet while the packet is being moved into the envelope. These drag forces are often the cause of jams or incomplete insertions in the system. It is thus advantageous and desirable to provide a method and system for envelope insertion using insertion fingers wherein the drag forces can be substantially reduced.
Another problem which limits the performance of insertion fingers is the fact that envelopes can be very sensitive to the relative humidity in the air. Under certain humidity conditions, the envelopes can warp or curl, which makes it particularly difficult to insure that all of the insertion fingers enter the throat of the envelope without jamming or damaging the throat of the envelope. It is, thus, advantageous and desirable to provide a set of fingers which can tolerate a high degree of warp or curl on envelopes with a wide range of envelope sizes, shapes, with a wide range of throat shapes without operator adjustments.